Coglings are super cute to play around with. I think it helped to assign it similar statistics of an existing 5e creature, which allowed them to be a sort-of-familiar without rehashing the full spell. Unfortunately they were hard to draw and took a long time.
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Coglings are a common sight aboard the Cogwork Citadel, built as tiny helpers for the inhabitants' works. Their appearances often reflect creatures on the Material Plane out of whimsy. The dracog is of a higher quality make - more independent and tougher to control, but serves as an excellent source of light, heat, and combat prowess for all situations.
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Cogling Dracog
Wondrous item, rare
In its deactivated state, this cogling is folded into a compact spheroid. While holding the cogling, you can use an action to activate it, unfurling into a mechanical creature called a dracon.
The cogling uses the statistics of a pseudodragon, except it is an unaligned construct that doesn't speak and does not have attacks — instead, it can use an action to create a fire as if with the produce flame cantrip, allowing it to hold a flame in its mouth or attack with it using its Wisdom modifier (spell save DC 15). The cogling obeys your commands and is friendly to you and your allies.
The cogling remains active for up to 1 hour, after which it deactivates. You can activate the cogling once, and can't do so again until it recharges at the next dawn. If it is reduced to 0 hit points, the cogling also cannot be activated again until it is repaired using tinker's tools and materials worth 5 gp.
Very Rare Variant. The cogling's maximum hit points increase by 10 and its AC becomes 17 instead of 13.